This application claims the benefit of a priority claim under 35 USC 119 to French Patent Application No. 01 08125 filed Jun. 20, 2001, the entire contents of which are hereby incorporated by reference.
This invention is directed to the field of electrical circuits, in particular to electrical junctions. More particularly, this invention is directed to high-voltage circuits or junctions, and more specifically to such circuits or junctions as used in radiology. Still further, this invention is directed to a coating element for an electrical circuit or junction.
In high-voltage circuits carrying high voltages on the order of several tens of kilovolts, the parts in the form of points are the site of very high electric field densities. Such densities sometimes lead to a breakdown between the points and ground potential. To avoid breakdown at the points, the points are tipped with balls having a greater radius of curvature than the points thereby substantially reducing the surface density of the electric field per unit area and hence the risk of breakdown is diminished. Such a practice, comprising xe2x80x9croundingxe2x80x9d the edges of the junctions, is difficult and costly to implement at all the points of the electrical circuit or junction that may give rise to the breakdown. For the same reason, the diameter of the connecting wires is increased to lessen the electric field density per unit area of the conductor wire. However, the conductors are difficult to handle because of their diameter, and hence costly to manufacture.
An embodiment of the invention provides a coating element for an electrical circuit or junction that will substantially diminish the surface electric field density at the periphery of the coating element.
In an embodiment of the invention, the electrical junction is surrounded with a coating element in a plastic material laden or in which there is dispersed conductive particles.
In an embodiment of the invention, the plastic material may be a polymer, an elastomer, a polyurethane or a silicone, and the conductive particles may be a powder of a metal such as aluminum or stainless steel or graphite. In an embodiment of the invention, the electrical conductor material has an electrical resistivity between about 1 ohm-cm and about 100 kilohm-cm.
In an embodiment of the invention, the coating element is yielding so as to adapt to the shape of the electrical circuit or junction.